Igor Sikorsky, a Russian-American engineer, is widely recognized as the inventor of the first successful helicopter, the VS-300, which flew in 1940.

The rotor blades of a helicopter are designed to generate lift, which is the force that opposes gravity and allows the helicopter to ascend and descend.

The spinning motion of a helicopter's rotor blades is referred to as rotation. This rotation generates the lift necessary for flight.

The tail rotor of a helicopter serves primarily to counteract the torque generated by the main rotor, preventing the helicopter from spinning uncontrollably.

VTOL (Vertical Take-Off and Landing) is the term used to describe a helicopter's ability to take off, hover, and land vertically, without the need for a runway.

Most helicopters have a maximum speed in the range of 100-150 mph (160-240 km/h), although some specialized helicopters can reach higher speeds.

The United States is renowned for its extensive use of helicopters in both military and civilian operations, with a large fleet of helicopters operated by the armed forces, law enforcement agencies, and various civilian organizations.

Vortex ring state is the term used to describe the phenomenon where a helicopter's rotor blades become overloaded and stall, causing a loss of lift and control. This can occur during certain maneuvers, such as rapid descents or tight turns.

The cyclic control of a helicopter is primarily used to control the helicopter's pitch and roll, allowing the pilot to change the helicopter's attitude and direction of flight.

Utility helicopters are commonly used for search and rescue operations due to their versatility, maneuverability, and ability to carry specialized equipment and personnel.

Sideward flight is the term used to describe a helicopter's ability to fly sideways or backwards, achieved by tilting the rotor disc and using the tail rotor to control direction.

Most helicopters have a maximum altitude in the range of 5,000-10,000 feet (1,500-3,000 meters), although some specialized helicopters can reach higher altitudes.

Vortex ring state is the term used to describe the phenomenon where a helicopter's rotor blades become overloaded and stall, causing a loss of lift and control. This can occur during certain maneuvers, such as rapid descents or tight turns.

The collective control of a helicopter is primarily used to control the helicopter's altitude, allowing the pilot to ascend, descend, or hover at a desired altitude.

Attack helicopters are specifically designed for military operations, equipped with weapons and advanced avionics for combat missions.